This invention relates to a dental elevator employed for tooth extraction.
The conventional dental elevators which are commercially available comprise a holder portion, a stem portion and a beak portion. These dental elevators which are popularly called T-shape (No. 1-No. 8) or #6 are generally classified into the following groups depending on the shape of the respective beak portions, namely (a) a straight beak, (b) warped beak, (c) bayonet beak, and (d) bent beak.
The width of the beak portion at the extremity thereof varies from 2 mm to 4 mm in the order of 0.5 mm and the shape of the extremity is usually either semi-circular or convex.
In a tooth-extracting operation using the above-mentioned dental elevator, as shown in FIG. 1, the beak portion of the elevator (11) is urgingly inserted in the periodontal cavity (23) and then the tooth is dislocated by the wedge action and the lever action of the elevator (11), thereby extracting the tooth. In this operation, however, as shown in the drawing, since the extremity (19) of the beak portion (17) which is attached to the holder portion (13) is provided with a semi-circular or gradually protruded convex shape, even when the dental root is urgingly lifted by the lever action using the periphery (21) of alveolar bone which is located opposite to the surface of the dental root (25) as the fulcrum of the lever, the beak extremity (19) cannot firmly engage the tooth. Therefore, the dentist may have to repeat the above lifting operations many times before completion of the tooth extraction.
Furthermore, since the beak portion of the conventional dental elevator slips during the operation, there is a good chance that the elevator injures the portions of the mouth surrounding the tooth to be extracted. It is considered that although the wedge action forms one of the essential functions in extracting the tooth, such conventional elevator cannot effect the above function efficiently due to the convex or round semi-circular extremity (19) of the beak portion.
The operation with these dental elevators is eventually very cumbersome and results in discomfort to the doctor as well as the patient.
It is an object of the present invention to provide a novel dental elevator which can firmly engage with the dental root without incurring slipping thereof, whereby the tooth can be readily extracted utilizing the wedge and lever actions efficiently.